1 files changed, 204 insertions, 37 deletions

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 328b00305426..60aeeb56948f 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -8,6 +8,7 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/pm.h>
+#include <linux/memblock.h>
 
 #include <asm/elf.h>
 #include <asm/vdso.h>
@@ -17,10 +18,11 @@
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 
+#include <xen/xen.h>
 #include <xen/page.h>
 #include <xen/interface/callback.h>
-#include <xen/interface/physdev.h>
 #include <xen/interface/memory.h>
+#include <xen/interface/physdev.h>
 #include <xen/features.h>
 
 #include "xen-ops.h"
@@ -33,6 +35,44 @@ extern void xen_sysenter_target(void);
 extern void xen_syscall_target(void);
 extern void xen_syscall32_target(void);
 
+/* Amount of extra memory space we add to the e820 ranges */
+phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
+
+/* 
+ * The maximum amount of extra memory compared to the base size.  The
+ * main scaling factor is the size of struct page.  At extreme ratios
+ * of base:extra, all the base memory can be filled with page
+ * structures for the extra memory, leaving no space for anything
+ * else.
+ * 
+ * 10x seems like a reasonable balance between scaling flexibility and
+ * leaving a practically usable system.
+ */
+#define EXTRA_MEM_RATIO         (10)
+
+static void __init xen_add_extra_mem(unsigned long pages)
+{
+        unsigned long pfn;
+
+        u64 size = (u64)pages * PAGE_SIZE;
+        u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
+
+        if (!pages)
+                return;
+
+        e820_add_region(extra_start, size, E820_RAM);
+        sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+
+        memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
+
+        xen_extra_mem_size += size;
+
+        xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
+
+        for (pfn = PFN_DOWN(extra_start); pfn <= xen_max_p2m_pfn; pfn++)
+                __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+}
+
 static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
                                               phys_addr_t end_addr)
 {
@@ -69,7 +109,7 @@ static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
                 WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n",
                      start, end, ret);
                 if (ret == 1) {
-                        set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+                        __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
                         len++;
                 }
         }
@@ -82,16 +122,18 @@ static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
                                                      const struct e820map *e820)
 {
         phys_addr_t max_addr = PFN_PHYS(max_pfn);
-        phys_addr_t last_end = 0;
+        phys_addr_t last_end = ISA_END_ADDRESS;
         unsigned long released = 0;
         int i;
 
+        /* Free any unused memory above the low 1Mbyte. */
         for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
                 phys_addr_t end = e820->map[i].addr;
                 end = min(max_addr, end);
 
-                released += xen_release_chunk(last_end, end);
-                last_end = e820->map[i].addr + e820->map[i].size;
+                if (last_end < end)
+                        released += xen_release_chunk(last_end, end);
+                last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
         }
 
         if (last_end < max_addr)
@@ -101,24 +143,140 @@ static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
         return released;
 }
 
+static unsigned long __init xen_set_identity(const struct e820entry *list,
+                                             ssize_t map_size)
+{
+        phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS;
+        phys_addr_t start_pci = last;
+        const struct e820entry *entry;
+        unsigned long identity = 0;
+        int i;
+
+        for (i = 0, entry = list; i < map_size; i++, entry++) {
+                phys_addr_t start = entry->addr;
+                phys_addr_t end = start + entry->size;
+
+                if (start < last)
+                        start = last;
+
+                if (end <= start)
+                        continue;
+
+                /* Skip over the 1MB region. */
+                if (last > end)
+                        continue;
+
+                if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) {
+                        if (start > start_pci)
+                                identity += set_phys_range_identity(
+                                                PFN_UP(start_pci), PFN_DOWN(start));
+
+                        /* Without saving 'last' we would gooble RAM too
+                         * at the end of the loop. */
+                        last = end;
+                        start_pci = end;
+                        continue;
+                }
+                start_pci = min(start, start_pci);
+                last = end;
+        }
+        if (last > start_pci)
+                identity += set_phys_range_identity(
+                                        PFN_UP(start_pci), PFN_DOWN(last));
+        return identity;
+}
 /**
  * machine_specific_memory_setup - Hook for machine specific memory setup.
  **/
-
 char * __init xen_memory_setup(void)
 {
+        static struct e820entry map[E820MAX] __initdata;
+        static struct e820entry map_raw[E820MAX] __initdata;
+
         unsigned long max_pfn = xen_start_info->nr_pages;
+        unsigned long long mem_end;
+        int rc;
+        struct xen_memory_map memmap;
+        unsigned long extra_pages = 0;
+        unsigned long extra_limit;
+        unsigned long identity_pages = 0;
+        int i;
+        int op;
 
         max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
+        mem_end = PFN_PHYS(max_pfn);
+
+        memmap.nr_entries = E820MAX;
+        set_xen_guest_handle(memmap.buffer, map);
+
+        op = xen_initial_domain() ?
+                XENMEM_machine_memory_map :
+                XENMEM_memory_map;
+        rc = HYPERVISOR_memory_op(op, &memmap);
+        if (rc == -ENOSYS) {
+                BUG_ON(xen_initial_domain());
+                memmap.nr_entries = 1;
+                map[0].addr = 0ULL;
+                map[0].size = mem_end;
+                /* 8MB slack (to balance backend allocations). */
+                map[0].size += 8ULL << 20;
+                map[0].type = E820_RAM;
+                rc = 0;
+        }
+        BUG_ON(rc);
 
+        memcpy(map_raw, map, sizeof(map));
         e820.nr_map = 0;
+        xen_extra_mem_start = mem_end;
+        for (i = 0; i < memmap.nr_entries; i++) {
+                unsigned long long end;
+
+                /* Guard against non-page aligned E820 entries. */
+                if (map[i].type == E820_RAM)
+                        map[i].size -= (map[i].size + map[i].addr) % PAGE_SIZE;
+
+                end = map[i].addr + map[i].size;
+                if (map[i].type == E820_RAM && end > mem_end) {
+                        /* RAM off the end - may be partially included */
+                        u64 delta = min(map[i].size, end - mem_end);
+
+                        map[i].size -= delta;
+                        end -= delta;
+
+                        extra_pages += PFN_DOWN(delta);
+                        /*
+                         * Set RAM below 4GB that is not for us to be unusable.
+                         * This prevents "System RAM" address space from being
+                         * used as potential resource for I/O address (happens
+                         * when 'allocate_resource' is called).
+                         */
+                        if (delta &&
+                                (xen_initial_domain() && end < 0x100000000ULL))
+                                e820_add_region(end, delta, E820_UNUSABLE);
+                }
 
-        e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM);
+                if (map[i].size > 0 && end > xen_extra_mem_start)
+                        xen_extra_mem_start = end;
+
+                /* Add region if any remains */
+                if (map[i].size > 0)
+                        e820_add_region(map[i].addr, map[i].size, map[i].type);
+        }
+        /* Align the balloon area so that max_low_pfn does not get set
+         * to be at the _end_ of the PCI gap at the far end (fee01000).
+         * Note that xen_extra_mem_start gets set in the loop above to be
+         * past the last E820 region. */
+        if (xen_initial_domain() && (xen_extra_mem_start < (1ULL<<32)))
+                xen_extra_mem_start = (1ULL<<32);
 
         /*
-         * Even though this is normal, usable memory under Xen, reserve
-         * ISA memory anyway because too many things think they can poke
+         * In domU, the ISA region is normal, usable memory, but we
+         * reserve ISA memory anyway because too many things poke
          * about in there.
+         *
+         * In Dom0, the host E820 information can leave gaps in the
+         * ISA range, which would cause us to release those pages.  To
+         * avoid this, we unconditionally reserve them here.
          */
         e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
                         E820_RESERVED);
@@ -129,29 +287,43 @@ char * __init xen_memory_setup(void)
          *  - xen_start_info
          * See comment above "struct start_info" in <xen/interface/xen.h>
          */
-        reserve_early(__pa(xen_start_info->mfn_list),
+        memblock_x86_reserve_range(__pa(xen_start_info->mfn_list),
                       __pa(xen_start_info->pt_base),
                         "XEN START INFO");
 
         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 
-        xen_return_unused_memory(xen_start_info->nr_pages, &e820);
+        extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
 
-        return "Xen";
-}
+        /*
+         * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
+         * factor the base size.  On non-highmem systems, the base
+         * size is the full initial memory allocation; on highmem it
+         * is limited to the max size of lowmem, so that it doesn't
+         * get completely filled.
+         *
+         * In principle there could be a problem in lowmem systems if
+         * the initial memory is also very large with respect to
+         * lowmem, but we won't try to deal with that here.
+         */
+        extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
+                          max_pfn + extra_pages);
 
-static void xen_idle(void)
-{
-        local_irq_disable();
-
-        if (need_resched())
-                local_irq_enable();
-        else {
-                current_thread_info()->status &= ~TS_POLLING;
-                smp_mb__after_clear_bit();
-                safe_halt();
-                current_thread_info()->status |= TS_POLLING;
-        }
+        if (extra_limit >= max_pfn)
+                extra_pages = extra_limit - max_pfn;
+        else
+                extra_pages = 0;
+
+        xen_add_extra_mem(extra_pages);
+
+        /*
+         * Set P2M for all non-RAM pages and E820 gaps to be identity
+         * type PFNs. We supply it with the non-sanitized version
+         * of the E820.
+         */
+        identity_pages = xen_set_identity(map_raw, memmap.nr_entries);
+        printk(KERN_INFO "Set %ld page(s) to 1-1 mapping.\n", identity_pages);
+        return "Xen";
 }
 
 /*
@@ -170,7 +342,7 @@ static void __init fiddle_vdso(void)
 #endif
 }
 
-static __cpuinit int register_callback(unsigned type, const void *func)
+static int __cpuinit register_callback(unsigned type, const void *func)
 {
         struct callback_register callback = {
                 .type = type,
@@ -223,9 +395,6 @@ void __cpuinit xen_enable_syscall(void)
 
 void __init xen_arch_setup(void)
 {
-        struct physdev_set_iopl set_iopl;
-        int rc;
-
         xen_panic_handler_init();
 
         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
@@ -242,11 +411,6 @@ void __init xen_arch_setup(void)
         xen_enable_sysenter();
         xen_enable_syscall();
 
-        set_iopl.iopl = 1;
-        rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
-        if (rc != 0)
-                printk(KERN_INFO "physdev_op failed %d\n", rc);
-
 #ifdef CONFIG_ACPI
         if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
                 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
@@ -258,9 +422,12 @@ void __init xen_arch_setup(void)
                MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
                COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
 
-        pm_idle = xen_idle;
-
-        paravirt_disable_iospace();
+        /* Set up idle, making sure it calls safe_halt() pvop */
+#ifdef CONFIG_X86_32
+        boot_cpu_data.hlt_works_ok = 1;
+#endif
+        pm_idle = default_idle;
+        boot_option_idle_override = IDLE_HALT;
 
         fiddle_vdso();
 }